The present invention relates generally to agricultural harvesters having computerized controls and, more specifically, to structure and a method for initiating automatic control of a combine.
Numerous functions on modern agricultural harvesters are now being controlled automatically. For example, some combines include transducers which sense the amount of material entering the combine and provide signals to a controller to adjust the speed of the combine in response to changes in material to maintain a generally constant throughput. One such device is described in and commonly assigned U.S. patent application Ser. No. 09/812,651 titled THROUGHPUT CONTROL FOR COMBINES filed on Mar. 20, 2001. Throughput can be modified if a harvesting quality variable, such as grain loss or grain damage, differs from a desired quality target range over an extended period of time. In another and commonly assigned application, Ser. No. 09/918,266 entitled HARVESTER SPEED CONTROL WITH HEADER POSITION INPUT and filed Jul. 30, 2001, a conventional speed control adjusts harvester speed as a function of outputs of one or more sensors including a throughput sensor located downstream of the header. However, when the header is lowered, combine speed is immediately lowered to prevent a sudden increase in material downstream of the feeder housing input.
One problem with these and similar types of automatic harvester controls has been proper initiation of the automatic control features. For example, in combines with throughput controls, too much crop can enter the machine and cause unstable operation if automatic control is initiated too late. If the initiation is too early, productivity as well as operating stability can be compromised. A simple and reliable way to initiate automatic operation to avoid throughput variations and instability is required.
It is therefore an object of the present invention to provide an improved system for initiating automatic control of an agricultural harvester. It is a further object to provide such a system which overcomes the aforementioned problems.
It is another object of the present invention to provide an improved system for initiating automatic control of an agricultural harvester which eliminates or reduces automatic control instabilities and unnecessary slowing of the harvester when no crop is present at the crop processor input.
It is a further object of the invention to provide improved detection structure for providing a signal for initiating an automatic control function on a combine. It is another object to provide such a detection structure which provides an initiation signal in response to entry of crop material into the feeder house. It is yet another object to provide such a structure which also acts as an adjustable down stop for the feeder house drum.
To provide an automatic control system initiation signal, a crop presence signaling device is located between the harvesting platform and the input to the crop threshing and separating assembly to detect entry of crop material into the feeder house and provide an initiation signal to the controller. The controller is responsive to the initiation signal to begin the automatic control. In one embodiment, the signaling device includes proximity switch structure responsive to movement of the drum resulting from crop material entering the feeder house. As the drum moves upwardly with crop entry, the switch structure changes state. The controller recognizes the change of state as an indication that material to be processed soon will be entering the threshing and separating assembly and initiates automatic control in response to the indication. Unnecessary slowing of the combine and decreased productivity which otherwise would occur can be avoided when little or no crop is present at the feeder house drum. Initiation of automatic control is optimized so that crop loss and control instabilities are reduced or eliminated.